The ship’s operator, Costa Crociere, said the vessel had been following its regular course when it hit a submerged rock.

In a TV interview, ship’s captain Francesco Schettino said the rock was not marked on any maritime charts.

Police are investigating why the accident happened in calm conditions.

Divers

The honeymooning South Korean couple were located after rescuers heard voices from a cabin two decks down on the half-submerged ship late on Saturday. They were reached a few hours later.

The couple, both 29 years old, were both in good health when they were brought ashore.

The third survivor has been named as Manrico Gianpetroni, an Italian national and a senior member of the crew. He has serious leg injuries.

He was placed on a stretcher and winched up to a rescue helicopter, to be taken to hospital on the mainland.

Two French passengers and a Peruvian crew member died, and another 30 people were injured, two seriously.

Divers are continuing to search the ship, which is lying on its side near the Tuscan island of Giglio.

The South Korean man was brought ashore on a rescue boat, after being found with his wife

The president of Costa Cruises, Gianni Onorato, said the main task for the company was now to assist survivors and help repatriate them.

He said it was difficult to determine what had happened, but that the ship had experienced a blackout after hitting “a big rock”.

Mr Onorato added: “We will be working in full transparency with Italian authorities” to understand the causes of the disaster.

He said normal lifeboat evacuation had become “almost impossible” because the ship had listed so quickly.

Francesco Schettino, the 52-year-old captain, had worked for Costa Cruises for 11 years.

The chief prosecutor in the city of Grosseto told reporters that Capt Schettino “very ineptly got close to Giglio”, according to Italy’s Ansa news agency.

Shaken

Analysis

Richard Westcott BBC transport correspondent

Investigators will now look into every aspect of this accident, but one of the key elements they will examine will be the electrical systems.

Modern ships tend to use electrical generators to drive the engines, so a power cut can leave the captain unable to steer away from danger.

Human error could also be a factor, and there will also be concern at the speed which the ship listed on to its side. Not only would that have been frightening, it seems to have affected the crew’s ability to launch some of the lifeboats.

All ships have to meet safety standards set out by the International Maritime Organisation. Crews are trained to deal with emergencies, and cruise companies stress this kind of accident is rare.